api: overhaul pointer API

- Rename `CursorMoved` to `PointerMoved`.
- Rename `CursorEntered` to `PointerEntered`.
- Rename `CursorLeft` to `PointerLeft`.
- Rename `MouseInput` to `PointerButton`.
- Add `position` to every `PointerEvent`.
- Remove `Touch`, which is folded into the `Pointer*` events.
- New `PointerType` added to `PointerEntered` and `PointerLeft`,
  signifying which pointer type is the source of this event.
- New `PointerSource` added to `PointerMoved`, similar to `PointerType`
  but holding additional data.
- New `ButtonSource` added to `PointerButton`, similar to `PointerType`
  but holding pointer type specific buttons. Use
  `ButtonSource::mouse_button()` to easily normalize any pointer button
  type to a generic mouse button.
- In the same spirit rename `DeviceEvent::MouseMotion` to `PointerMotion`.
- Remove `Force::Calibrated::altitude_angle`.

Fixes #3833.
Fixes #883.
Fixes #336.

Co-authored-by: Kirill Chibisov <contact@kchibisov.com>

src/platform_impl/web/event.rs

@@ -1,5 +1,7 @@
-#[derive(Debug, Copy, Clone, Eq, PartialEq, PartialOrd, Ord, Hash)]
-pub struct DeviceId(u32);
+use crate::event::FingerId as RootFingerId;
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct DeviceId(pub(crate) u32);
 
 impl DeviceId {
     pub fn new(pointer_id: i32) -> Option<Self> {
@@ -34,3 +36,9 @@ impl FingerId {
         self.primary
     }
 }
+
+impl From<FingerId> for RootFingerId {
+    fn from(id: FingerId) -> Self {
+        Self(id)
+    }
+}